Top-heat oven with selective browning

ABSTRACT

A dual-heating element oven comprising a bake heating element and a broil heating element in combination with a control system that permits the selective alteration of the output of the broil heating element by the user to control the browning of a food item during the bake cycle.

BACKGROUND OF INVENTION

1. Field of the Invention

In one aspect, the invention relates to an oven for baking food items,and more specifically, to an oven capable of selectively browning a fooditem.

2. Description of the Related Art

Electric and gas cooking ovens are old and well-known. They comprise achassis in which is located a baking cavity having one or more racks forsupporting a food item. Such ovens initially used a single heatingelement located in the bottom of the baking cavity, which is known asthe bake heating element. The heat from the bake heating element wouldtravel to the top of the baking cavity, predominately by convection. Adisadvantage of the single element was that a temperature gradient candevelop between the bottom and the top of the oven because of the timethat it took for the heat to travel to the top of the cavity. Themagnitude of the temperature gradient is exacerbated by the use of acooking dish which typically covered a large portion of the bakingcavity cross section and disrupted the flow of heat from the bottom tothe top of the baking cavity. The presence of the pan tended to createan airflow stagnation location at the bottom of the pan and forced theheated air to the perimeter of the baking cavity, which resulted in adead heating zone directly above the dish where the air has a lowertemperature. The temperature gradient with and without the dish wasoften substantial enough to adversely affect the baking performance ofthe oven.

One popular solution to eliminating the temperature gradient was to usea second heating element in the top of the oven. Such heating elementsare also used to broil foods by directly radiating heat onto the uppersurface of the food item. These heating elements are generally referredto as “broil heating elements” even when used during baking because oftheir initial historical use for broiling.

A disadvantage of the using the broil heating element during baking isthat the food item receives a much larger amount of directly radiatedheat (top heat) from the broil heating element. The amount of radiatedheat is attributable to the close proximity of the broil heating elementto the upper surface of the food item, and the upper surface of the fooditem is not protected from direct radiation like the bottom surface,which is normally protected by a pan or some other covering to preventdripping.

The extra top heat increases the rate and degree of browning of the fooditem as compared to when only the bake heating element is used. Theextra top heat, while greatly beneficial for maintaining a more eventemperature distribution in the oven resulting in a reduced temperaturegradient and in better baking performance, is not useful for food itemsthat require browning, like pies, cookies and the like.

There is still a need for an oven that has the even temperaturedistribution associated with dual heating elements yet maintains thebrowning performance of the single heating element.

SUMMARY OF INVENTION

The invention solves the problem of providing user control of thetop-heat radiated by an oven by permitting the user to selectivelyincrease or decrease the radiated top heat. The decrease in radiated topheat is especially important in enhancing the browning performanceproblem of a dual-heating-element oven. The invention relates to an ovenfor baking food according to a bake cycle, which typically has a userselect time and temperature parameters. The oven comprises a housingthat defines an open-faced baking cavity, which is formed by opposingtop and bottom walls, opposing sidewalls that extend between the top andbottom walls, and a rear wall opposing the open face. A door is movablymounted to the housing for movement between an opened to a closedposition to thereby selectively close the baking cavity open face. Abake heating element is positioned adjacent the bottom wall forintroducing heat energy (“bottom heat”) into the baking cavity. A broilheating element is positioned adjacent the top wall for introducing heatenergy (“top heat”) into the top of the baking cavity. A controller isprovided for controlling the activation of the top heating element bycycling the broil heating element ON and OFF to implement the bakecycle. The controller has a user-operable switch, the selection of whichreduces/increases the top heat radiated by the broil heating elementwhile the switch is selected. The deselection of the switch terminatesthe reduced/increased top heat. The selection and deselection of theswitch permits the user to selectively control the top heat and thuscontrol the browning performance of the oven.

The controller can control the activation of both the broil and the bakeheating elements by cycling the broil and bake elements ON and OFFaccording to a predetermined protocol to implement the bake cycleaccording to the user-selected time and temperature. The selection ofthe user-operable switch reduces/increases the top heat radiated by thebroil heating element relative to top heat output according to thepredetermined protocol.

The reduction/increase of the top heat radiated by the broil heatingelement can be accomplished in a variety of different ways. For example,the selection of the user-operable switch can reduce/increase theoverall time that the broil heating element is on relative to theoverall time the broil heating element would be on under thepredetermined protocol. The reduced/increased time that the broilheating element is on can be accomplished by either reducing/increasinga broil temperature set point for the broil heating element orreducing/increasing the duty cycle for the broil heating element, ascompared to the duty cycle under the predetermined protocol. Thereduction/increase of the broil temperature set point and the duty cyclecan be combined to reduce/increase the top heat output of the broilheating element.

The invention also relates to a method for controlling the browningperformance of an oven comprising a baking cavity having a broil heatingelement positioned near the top wall of the oven cavity for radiatingtop heat into the baking cavity, a bake heating element positioned neara bottom wall of the baking cavity for radiating bottom heat into thebaking cavity, and a controller for actuating the bake and broil heatingelements ON and OFF. The method comprises implementing a baking cyclethat maintains a temperature of the baking cavity at a predeterminedbake temperature by controlling the cycling of the bake and broilheating elements and selectively reducing/increasing the cumulative topheat radiated by the broil heating element for at least part of the bakecycle in response to a user input.

The top heat radiated by the broil heating element can bereduced/increased for the entire bake cycle in response to the userinput. Also, the predetermined bake temperature is typically selected bythe user.

The implementation of the bake cycle comprises having a broiltemperature set point corresponding to the predetermined baketemperature. The selective reduction/increase of top heat can beaccomplished by reducing/increasing the broil temperature set point.Also, the implementation of the bake cycle can further comprise adding aduty cycle for the broil heating element based on the predetermined baketemperature.

The duty cycle can vary as a function of the magnitude of thepredetermined bake temperature. The predetermined bake temperature canalso be limited to at least two temperature ranges, with the duty cyclevarying as a function of the temperature range. The reduction of thebroil temperature set point can also vary as a function of thetemperature range.

In another aspect, the invention relates to an oven for baking foodaccording to a bake cycle having user selected time and temperatureparameters. The oven comprises a housing that defines a baking cavity inwhich a bake heating element is positioned adjacent a lower portion ofthe baking cavity for introducing bottom heat into the baking cavity anda broil heating element positioned adjacent an upper portion of thebaking cavity for introducing top heat into the baking cavity. A controlpanel is provided comprising a bake mode selector for selecting thedesired bake mode, a bake temperature selector for selecting the desiredbaking temperature, a bake time selector for selecting the desired baketime, and a top heat adjustment selector for adjusting the top heatrelative to the amount of top heat determined by the selected bake mode.The selection of the top heat adjustment selector on the control panelcan increase or decrease the outputted top heat relative to theoutputted top heat according to the selected bake mode.

BRIEF DESCRIPTION OF DRAWINGS

In the drawings: FIG. 1 is a perspective view looking into the bakingcavity for an oven according to the invention having a broil heatingelement at the top of the baking cavity and a bake heating elementlocated at the bottom portion of the baking cavity and dual temperaturesensors, with one temperature sensor located near the broil heatingelement and the other located near the bake heating element.

FIG. 1A is a perspective view of the baking cavity of FIG. 1, wherein afood product in a baking pan is placed on the rack in the baking cavity,and arrows show the general heat track around the baking pan and foodproduct when the bake heating element is activated, whereby a deadheating zone is defined above the food product.

FIG. 1B is a perspective view of the baking cavity of FIG. 1, wherein afood product in a baking pan is placed on the rack in the baking cavity,and arrows show the general heat track around the baking pan and foodproduct when the broil heating element is activated, thus reducing thenegative baking effects of the dead heating zone above the food productshown in FIG. 1A.

FIG. 2 is a block diagram showing the general components of the oven ofFIG. 1 configured for electric-based heating elements.

FIG. 3 is a block diagram showing the general components of the oven ofFIG. 1 configured for gas-based heating elements.

FIG. 4 illustrates a sample control panel for use with either the gas orelectric ovens shown in FIGS. 3 and 4 and incorporates a CHOICE BAKEselector in the form of a button for selecting the reduced top heatcooking cycle according to the invention.

FIG. 4A illustrates a first alternative control panel having controlknobs for selecting the bake mode and the temperature and a CHOICE BAKEbutton for selecting the reduced top heat.

FIG. 4B illustrates a second alternative control panel similar to thefirst alternative, except that the CHOICE BAKE selector is incorporatedwith the bake mode knob.

FIG. 5 is a flowchart for controlling the temperature of the bakingcavity of the ovens shown in FIGS. 1-3, specifically showing the stepsof gathering information from a user, determining specific parametersfor the bake mode and preheating the baking cavity of the oven usingthose set parameters in proceeding to the flowchart shown in FIG. 6.

FIG. 6 is a flowchart continuing from point “A” of FIG. 5 and shows amain set of steps for checking the temperature sensors shown in FIG. 2adjacent each of the bake and broil heating elements and callingsubprocess in FIGS. 7, 8, 9 and 10 as indicated by subprocess calls “B,”“D,” “E,” and “G,” respectively.

FIG. 7 is a flowchart showing the method steps performed if subprocess“B” is called from FIG. 6.

FIG. 8 is a flowchart showing the method steps performed if subprocess“D” is called from FIG. 6.

FIG. 9 is a flowchart showing the method steps performed if subprocess“E” is called from FIG. 6.

FIG. 10 is a flowchart showing the method steps performed if subprocess“G” is called from FIG. 6.

DETAILED DESCRIPTION

FIG. 1 illustrates an oven 10 incorporating a selective control of thetop heat according to the invention. The oven 10 is primarily describedin the context of reducing the top heat to improve overall browningperformance, although the invention applies equally as well toincreasing the top heat.

The oven 10 comprises an open-face housing defining a baking cavity 12,with the open face enclosed by a hinged door 14. The open face housingis formed by opposing top and bottom walls 16, 18, opposing side walls20, 22, and a rear wall 24. A broil heating element 26 is mountedadjacent the upper wall of the baking cavity 12 and a bake heatingelement 28 is mounted adjacent the lower wall of the baking cavity. Theside walls 20, 22 are provided with rack supports 29 extending generallyin horizontal fashion depth-wise into the baking cavity 12 along theside walls 20, 22 for supporting a baking rack 31 thereon.

In FIGS. 1-2, the oven 10 is shown configured for electric-based heatingelements and in FIG. 3 for gas-based heating elements. In bothconfigurations a broil temperature sensor 30 is located adjacent to abroil heating element 26 and a bake temperature sensor 32 is locatedadjacent a bake heating element 28. The broil temperature sensor 30 andthe bake temperature sensor 32 are interconnected to a controller 34.

FIGS. 2-3 show block diagrams of electric- and gas-based ovens, 10,respectively, since the particular mechanical interconnection andassembly of the elements of the block diagrams shown in FIGS. 2-3 arenot critical to the invention and any of the well-known componentsmaking up prior art ovens will suffice, as this invention relates to themethod of controlling the top heat or the radiated heat from the broilheating element to improve the browning performance of the oven.

With reference to FIGS. 1-3, the general components making up the oven10 according to the invention include an oven chassis 36 that supportsthe components making up the oven 10 on a floor 38. An anti-tip bracket40, mechanically couples the chassis 36 to either the floor or the wallto prevent the oven from tipping when a large weight is placed on thedoor 14. The door 14 is typically mounted to the chassis 36 by a hinge42 and maintains the integrity of the baking cavity 12 by a seal 44 thatis preferably effective in preventing heat from escaping the cavity 12.

A warming/storage drawer 46 is typically provided at a lower portion ofthe chassis 36 and mounted thereto by conventional glides 48 permittingslidable movement of the warming/storage drawer 46 relative to thechassis 36. The warming/storage drawer 46 is typically provided with itsown heating element 50 interconnected to the controller 34 and actuatedby the controller 34 via a signal from a temperature sensor 52 locatedwithin the warming/storage drawer 46.

The oven 10 can also include a conventional cooktop 54 typicallycomprising several cooktop burners or elements 56. In the electric-basedoven 10 shown in FIG. 3, the cooktop burners/elements 56 areinterconnected to an electric power supply 58 via a switch 60 as isconventionally known. In the gas-based oven 10 shown in FIG. 4, thecooktop burners/elements 56 are interconnected to a gas supply line 62via a regulator 64 and several valves 66 also as is conventionallyknown. In both the embodiments of FIGS. 3-4, the power supply 58 is alsointerconnected to the controller 34 to supply power thereto.

A latch 65 is also mounted on the chassis 36 and is preferablyinterconnected to the controller 34 and the door 14. A user 67 manuallyactuates the latch 65 to latch the door to the chassis 36 to lockablyenclose the cavity 12. Further, the controller 34 can send a signal tothe latch 65 to automatically lock the door 14 to the chassis 36enclosing the cavity during oven cleaning operations, thus preventingthe user 67 from opening the door 14.

In the electric-based oven 10 shown in FIG. 2, the broil heating element26 and the bake heating element 28 are directly interconnected to thecontroller 34, which controls the supply of power from the power supply58 to selectively heat the cavity 12 in a controlled fashion. In thegas-based version shown in FIG. 3, the broil heating element 26 and thebake heating element 28 are interconnected to the controller 34 via agas control assembly 68 that comprises a spark module 70 (i.e., anigniter) for passing a spark to an electrode 72 which, in turn,interacts with a volume of gas released by a solenoid valve 74 that isinterconnected to the gas supply line 62 via the regulator 64.

The controller 34 is interconnected to a control panel 76 mounted to thechassis 36 that contains among other things, actuator devices such ascontrol knobs that allow the user 67 to set, among other things, theparticular heating mode of the oven 10 (e.g., BAKE, BROIL, CLEAN, etc.)and, to the extent the user has selected either the bake or broilheating modes, a target temperature set point at which the user desiresto cook food products in the baking cavity 12.

The control panel 76 is shown in greater detail in FIG. 4. The controlpanel 76 comprises a variety of keypads for selecting or inputtingcooking cycle related data. For example, a cycle keypad 90 is providedand comprises buttons labeled BAKE, CUSTOM BROIL, WARM, and CHOICE BAKE,which correspond to a particular cooking cycle. The depression of thebutton will initiate the corresponding cycle. For example, if atraditional bake cycle is desired, the user will depressed the BAKEbutton.

A data input keypad 91 is provided and includes buttons labeled TEMP,START TIME, STOP TIME, HR, and MIN. The START TIME and STOP TIME areused to program the start and stop times of a time bake cycle. The TEMP,HR, MIN buttons are toggle buttons which can provide for the entry ofthe cooking temperature, and cooking time in hours and minutes. Pressingthe top of each of the toggle buttons increases the value while pressingthe lower portion of the toggle buttons decreases the value.

A timer keypad 92 is provided for programming the timer function of theoven. The timer keypad comprises a TIMER SET button for initiating thetimer function and a TIMER OFF button for turning off the timerfunction. A CLOCK button is provided for setting the time of day for thetimer for use in a time bake cycle. Also, an AUTO CLEAN button isprovided for selecting the self cleaning mode for the oven.

A display 93 is provided and includes a temperature display 94, a timer95, and a series of indicators 96. As illustrated, the indicators arelighted text messages and include: HEAT, BAKE, BROIL, LOCKED, CLEAN,TIMER, ON. The HEAT indicator is illuminated when the heating element isactivated. The BAKE and BROIL indicators are illuminated when thecorresponding button in the cycle keypad is selected. The CLEANindicator is illuminated when the oven is in the self-cleaning cycle.The TIMER indicator is illuminated when the timer function is initiated.The ON indicator is illuminated when the oven is turned on.

Other miscellaneous buttons include the START, OFF, and OVEN LIGHTbuttons. The START button is depressed after the selection of any cycleto start the cycle. The OFF button is selected when it is desired tomanually terminate any selected cycle. The OVEN LIGHT button is selectedto turn on the light inside the cooking cavity.

FIG. 4A illustrates a first alternative control panel 76′ comprisingsubstantially the same data input keypad 91′ and timer keypad 92′, whichshare a TIME input button. The control panel further comprises a display93′ incorporating multiple status and mode indicators comprising text(COOK TIME/TIMED, CHOICE BAKE, BAKE, BROIL, HEAT, CLEAN, DOOR LOCKED,and DELAY START TIME) with a corresponding light. The display 93′includes a time display 95′, but does not include a temperature displayas does the control panel 76. Instead, a temperature dial or controlknob 160 is used. The knob 160 is rotated to the desired bakingtemperature to set the baking temperature.

The control panel 76′ also does not include a cycle keypad 90. Instead,the control panel 76′ includes a cycle dial or control knob 162. Theknob includes OFF, BAKE, and BROIL positions. By turning the knob to oneof these positions, the user can select that cycle. A separate CHOICEBAKE button is provided on the control panel 76′. The selection of theCHOICE BAKE button operates in the same manner as that described for thedisplay 76.

The control panel 76′ also comprises miscellaneous buttons, such asSTART and OFF.

The operation of the invention is described with respect to FIGS. 5-10and with reference to the control panel 76. The operation also appliesto the other control panels 76′ and 76″, the only difference being inhow the cycle, temperature, and CHOICE BAKE option are selected. Itshould also be noted that while push button switches and control knobsare shown in the displays, these terms are also meant to include andreference any type of suitable selector.

The operation of the invention is described with respect to FIGS. 5-10and with reference to the control panel 76. The operation also appliesto the other control panels 76′ and 76″, the only difference being inhow the cycle, temperature, and CHOICE bake option are selected. Itshould also be noted that while push button switches and control knobsare shown in the displays, these terms are also meant to include andreference any type of suitable selector.

FIGS. 5-10 illustrate a preferred protocol for implementing a bake cyclefor the dual element oven as disclosed. It should be noted that theinvention is not limited to the preferred protocol as described. TheCHOICE BAKE cycle and corresponding structure can be used with any typeof protocol for implementing a bake cycle. It should also be noted thatwhile the CHOICE BAKE cycle is illustrated as an option or alteration tothe selected bake cycle, the CHOICE BAKE cycle can be a completelyindependent cycle.

For the purposes of the flowcharts describing the inventive methodherein of FIGS. 4-10, it is assumed that the user 67 has accessed thecontrol panel 76 and set the heating mode of the oven to BAKE,preferably by selecting the BAKE button from the cycle keypad 80, andset a target temperature set point (i.e., the desired temperature towhich the baking cavity 12 is to be heated and closely controlled andmaintained at that temperature during the BAKE cycle) by using the TEMPbutton from the data input keypad 82.

If either control panel 76′ or 76″ is used, the target temperature setpoint TARGET_TEMP is set by the user 67 typically selecting from varioustemperatures in 5-50 degree increments in degrees F such as 150, 200,250, 300, 350, 400, 450, 500, with intervening 25 degree markings, forexample.

The method of controlling the temperature of the baking cavity 12 at theuser-selected target temperature set point TARGET_TEMP in the BAKE modeis shown at 100 in FIG. 5. Once these parameters are set by the user atstep 100, processing moves to step 102, wherein further bake modeparameters are determined by the controller 34 from a database 104. Thedatabase 104 can be any simple look-up table or a relational databasethat supplies data to the controller 34 based upon the make and/or modelof oven 10 employed. An example of the database 104 appears in thefollowing Table 1.

TABLE 1 Bake Method Temperature and Time Set Points (all Temperatures indegrees F. and times in seconds) A B C D E F G H I J K L Broil BakeBroil Bake Temp Preheat Set Ampl Set Ampli Cycle On Cycle On Band TargetBroil Bake Point itude Point tude Time Time Time Time Delta LOW 200 230230 188 1 182 1 60 15 60 60 6 250 280 280 238 1 232 1 60 15 60 60 6 300330 330 288 1 282 1 60 15 60 60 6 325 355 355 313 1 307 1 60 15 60 60 6MID 330 360 360 314 1 302 1 60 35 60 60 12 350 380 380 334 1 322 1 60 3560 60 12 400 430 430 384 1 372 1 60 35 60 60 12 440 470 470 424 1 412 160 35 60 60 12 HIGH 450 470 470 434 1 420 1 60 40 60 60 14 475 495 495459 1 445 1 60 40 60 60 14

The example database 104 shown in Table 1 has twelve columns labeledconsecutively by letters A-L. Column A in Table 1 corresponds to thetarget temperature set point TARGET_TEMP set by the user 67 on thecontrol panel 76. Table 1 contains several rows each corresponding tothe typical temperature settings used in baking and provided on thecontrol panel 76 for setting the desired target temperature set pointTARGET_TEMP. Table 1 shows several rows corresponding to these typicalvalues in degrees F including 200, 250, 300, 325, 330, 350, 400, 440,450 and 475. It should be known that this invention is not limited bythe values shown in Table 1 as these should be interpreted as merely anexample of the data used by the controller 34 and should not be limitingon the invention.

Table 1 also includes a first column which groups the rows of Table 1into low-, mid-, and high-temperature bands wherein the low-temperatureband ranges from 200-325° F., the mid-temperature band ranges from330-440° F. and the high-temperature band ranges from 450° F. andhigher. These groupings were made by trial selection. It has been foundthat particular heating ranges such as the low-, mid- andhigh-temperature bands shown in Table 1 each exhibit commoncharacteristics which allow certain equations to be attributedindividually to the two target temperatures falling within these targettemperature bands as will be further described below.

Columns B and C of the database 104 shown by example in Table 1 includetarget set temperature points for the broil heating element 26 and thebake heating element 28, respectively. These values represent thedesired targets to have the broil temperature sensor 30 and the baketemperature sensor 32 read during preheating of the oven 10. It will benoted that the preheat broil target temperature of column B and thepreheat bake target temperature of column C exceed the targettemperature of column A by 30, 30 and 20 for the low-, mid- andhigh-temperature bands, respectively.

It should not be limiting to this invention that the preheat broil andpreheat bake target temperatures are shown as equal values as it isequally contemplated that these values could differ under a differentoven preheating cycle. Further, the “overshoot” differences, i.e., theamount the preheat broil and preheat bake target temperatures of columnsB and C of the database 104 of Table 1 exceed the target temperature setpoint of Column A, can also be selected as different values withoutdeparting from the scope of this invention, as those values shown are byexample and not by limitation.

Columns D-E and F-G of the database 104 shown by example in Table 1contain a target set point and range amplitude for the broil heatingelement 26 and the bake heating element 28, as to be detected by thebroil temperature sensor 30 and the bake temperature sensor 32,respectively, during the BAKE mode as selected by the user 67 for aparticular target temperature set point TARGET_TEMP. These values permitthe controller 34 to calculate low-temperature limit andhigh-temperature limit set points for the broil heating element 26 andthe bake heating element 28.

For example, at a particular target temperature set point TARGET_TEMPselected by the user 67, the database 104 looks up a corresponding valuein Column A and sets a variable BROIL_SET to the value in Column D(e.g., 334° F. at a desired target temperature TARGET_TEMP of 350° F.).The controller 34 then calculates a broil heating elementlow-temperature limit BROIL_LTL by subtracting the amplitude in Column Efrom the set point temperature in Column D and calculates a broilheating element high-temperature limit BROIL_HTL by adding the amplitudein Column E to the broil set point temperature in Column D.

For example, at a particular target temperature set point TARGET_TEMPselected by the user 67, the database 104 looks up a corresponding valuein Column A and sets a variable BAKE_SET to the value in Column F (e.g.,322° F. at a desired target temperature set point TARGET_TEMP of 350°F.). The controller 34 then calculates a bake heating elementlow-temperature limit BAKE_LTL by subtracting the amplitude in Column Gfrom the set point temperature in Column F and calculates a bake heatingelement high-temperature limit BAKE_HTL by adding the amplitude inColumn G to the bake set point temperature in Column F.

Columns H and I define the duty cycle for the broil heating element 26,i.e., the length of time comprising the normal heating cycle of thebroil heating element 26 and the length of time (in seconds) that thebroil heating element 26 is on during that time. Column H represents thelength of time BROIL_CYCLE that the broil heating element 26 stays onupon a signal to activate the broil heating element 26 from thecontroller 34. Column I represents the amount of time in secondsBROIL_ON that the broil heating element is actually emitting heat duringthe BROIL_CYCLE. For example, at a desired target temperature of 350°,the broil heating element 26 has a total cycle time of 60 seconds(Column H at a target temperature set point of 350° from Column A) andthe broil heating element stays on approximately 35 seconds out of that60-second time (Column I at a desired target temperature set point of350° in Column A).

For the LOW temperature range, the BROIL_ON time is 15 seconds out of a60 second BROIL_CYCLE. For the MID and HIGH temperature ranges, theBROIL_ON time is 35 seconds and 40 seconds, respectively, for the sameBROIL_CYCLE value. Thus, as the temperature range increases, the broilheating element is kept on a greater amount, which will increase the topheat that is radiated directly onto the food item.

Columns J and K define the duty cycle for the bake heating element 28,i.e., the length of time comprising the normal heating cycle of the bakeheating element 28 and the length of time (in seconds) that the bakeheating element 28 is on during that time. Column J represents thelength of time BAKE_CYCLE that the bake heating element 28 stays on upona signal to activate the bake heating element 28 from the controller 34.Column K represents the amount of time in seconds BAKE_ON that the bakeheating element 28 is actually emitting heat during the BAKE_CYCLE. Forexample, at a desired target temperature of 350° the bake heatingelement 28 has a total cycle time of 60 seconds (Column J at a targettemperature set point of 350° from Column A) and the bake heatingelement 28 stays on approximately 35 seconds out of that 60-second time(Column K at a desired target temperature set point of 350° in ColumnA).

Column L is an optional column in the database which is essentially usedas a tool to conserve memory in the controller 34 by creating a valueDELTA in Column L which defines the relationship between the bake setpoint in Column F and the broil set point in Column D., i.e., DELTA inColumn L represents the number of degrees F by which the broil set pointof Column D exceeds the bake set point in Column F. Thus, if the DELTAvalue in Column L is employed, one of the broil set points in Column Dand the bake set point BAKE_SET in Column F is unnecessary as the otherof these two values could be calculated by adding or subtracting theDELTA value in Column L to either Column D or Column F.

Thus, memory can be conserved by employing the fewer bits to representthe DELTA value in Column L rather than the larger number of eitherColumn D or Column F (BROIL_SET or BAKE_SET) which requires more bits tostore this value. While this memory saving may not be a concern withcontrollers 34 with large amounts of RAM or ROM, this memory-savingtechnique can be significant for controllers 34 with smaller amounts ofmemory.

In summary, when the user sets the desired target temperature set pointTARGET_TEMP and selects the bake mode on the control panel 76 at step100, the processing moves to step 102 where the controller 34 looks upand calculates the following bake parameters from the database 104 shownby example in Table 1. All values in Table 1 are shown in degrees F andall times are shown in seconds. Also, in the following equations, acapital letter shown in parentheses (e.g., (D)) represents a value fromthe column identified by the letter in parentheses at the intersectionof the row corresponding to the desired target temperature set pointTARGET_TEMP set by the user 67 on the control panel 76.

BROIL_SET=(D) (or) (F)+(L);

BROIL_LTL=BROIL_SET (E);

BROIL_HTL=BROIL_SET+(E);

BAKE_SET=(F) (or) BROIL_SET (L);

BAKE_LTL=BAKE_SET (G);

BAKE_HTL=BAKE SET+(G);

BROIL_CYCLE=(H);

BROIL_ON=(I);

BAKE_CYCLE=(J);

BAKE_ON=(K); and

DELTA (if used)=(L).

The database 104 can also be used to look up the preheating target setpoint temperatures BROIL_PRE=(B) and BAKE_PRE=(C).

It is important to note that the parameters and the corresponding valuesshown in Table 1 are illustrative and not limiting to the invention. Theparticular values for each of the parameters can vary depending on theparticular oven characteristics, such as, for example: baking cavityvolume, broiler heating output, oven heating output, and desiredresponse time in the case of the initial temperature overshoot. Theparticular values for a given oven can be determined by standard testingprocedures.

Once these values are established, processing moves to step 106 in whichthe oven is preheated using the parameters looked up in the database 104in step 102. The preheat routine is relatively simple and relates toselectively actuating the broil heat element 26 until the broiltemperature sensor 30 reads an excess of BROIL_PRE and selectivelyactuating the bake heating element 28 until the bake temperature sensor32 reads an excess of BAKE_PRE. It is preferred that the broil heatingelement 26 and the bake heating element 28 be actuated independently ofeach other so that at no time the broil heating element 26 is on thesame time as the bake heating element 28, since the actuation of bothheating elements 16 and 18 at once can cause the rate of ambienttemperature rise in the baking cavity 12 to increase dramatically, oftenbeyond the ability of the controller 34 to compensate for this increase.It will also be understood that the broil heating element 26 and thebake heating element 28 are preferably actuated according to their dutycycles defined in columns H-I and J-K by the BROIL_CYCLE, BROIL_ON,BAKE_CYCLE and BAKE_ON parameters determined in step 102 by a look up tothe database 104.

Once the oven has preheated, typically by overshooting the desiredtarget temperature TARGET_TEMP, processing moves to a connectingflowchart in FIG. 6 via connector “A.” An overview of the controlprocess will be useful in understanding the detailed operation. Afterthe setting of the control parameters (FIG. 5), the broil and bakeheating elements 26 and 28 are activated to maintain the temperature ofthe cavity adjacent the corresponding broil and bake temperature sensors30 and 32 between the high and low temperature limit set points,respectively (FIG. 6).

It is preferred that neither the bake nor the broil heating element isactivated simultaneously (FIGS. 7-10) and priority is given to the bakeheating element (FIG. 7). In other words, if both the bake and broilheating elements require activation, the bake heating element isactivated even if the broil heating element must be turned off.

The benefits of alternate actuation of the bake and broil heatingelements (28 and 26) can be seen from an examination of FIGS. 2A and 2B.FIG. 2A is a perspective view of the baking cavity 12 of FIG. 2 whereina food product 80 in a baking pan 82 is placed on the rack 31 in thebaking cavity 12. As can be seen from FIG. 2A, arrows show the generalheat track around the baking pan 82 and food product 80 when the bakeheating element 28 is activated. Since the heat from the bake heatingelement 28 generally tracks around the baking pan 82 and food product 80and then generally rises vertically, a dead heating zone 84 is definedabove the food product 80 where the heat from the bake heating element28 does not effectively cook the food product 80. In the case of a lowtemperature item such as frozen poultry, this dead heating zone 84 cancause significant detriment to the cooking of the food product 82.

This invention addresses this problem by periodically activating thebroil heating element 26 based upon signals from the broil temperaturesensor 30 in addition to the periodic activation of the bake heatingelement 28 based upon signals from the bake temperature sensor 32. Thiscauses heat to be applied to the food product 80 from above as well asshown in FIG. 1B. The arrows in FIG. 1B show the general heat toward thefood product 80 from the broil heating element 26 directly through thedead heating zone 84 thus reducing the negative baking effects of thedead heating zone 84 above the food product 80.

FIG. 6 represents the main control routine for controlling thetemperature in the baking cavity 12 of the oven 10. Processing thenmoves to step 108 in which the controller accepts a signal BAKE_TEMPfrom the bake temperature sensor 32, which is indicative of thetemperature in the cavity 12 at the sensor 32 location. Processing movesto decision point 110 where it is determined whether BAKE_TEMP exceedsthe desired high temperature limit for the bake heating elementBAKE_HTL. If so, processing passes to the subprocess shown in FIG. 7 viaconnector “B” in FIG. 6. If not, processing moves to decision point 112.

At decision point 112, it is determined whether the value of the signalBAKE_TEMP emitted by the bake temperature sensor 32 is less than thedesired lower temperature limit for the bake heating element 28BAKE_LTL. If so, the subprocess shown in FIG. 8 is called via theconnector “D” shown in FIG. 6. If not, processing moves to step 114.

At step 114, the controller 34 receives a signal from the broiltemperature sensor 30 corresponding to the temperature BROIL_TEMP readby the broil temperature sensor 30. It should also be noted thatprocessing returns from the subprocess noted by “B” and the subprocessidentified by “D” to the method step shown in FIG. 6 by the connectorshown as “C” which returns the processing of these subprocesses to step114 as well.

Processing then moves to decision point 116. At decision point 116, thecontroller 34 determines whether the value BROIL_TEMP read in step 114exceeds the desired high temperature limit for the broil heating element26 BROIL_HTL. If so, the subprocess shown in FIG. 9 is called asindicated by connector “E” in FIG. 6. If not, processing passes todecision point 118.

At decision point 118, the controller 34 determines whether the valueread by the broil temperature sensor 30 BROIL_TEMP is less than thedesired lower temperature limit for the broil heating element 26BROIL_LTL. If so, the subprocess of FIG. 10 is called as indicated byconnector “G” on FIG. 6. If not, processing passes to the intermediatepoint indicated by connector “F” in FIG. 6, at which time processingloops back to step 108.

It should also be noted that the subprocess of FIG. 9, as indicated byconnector “E” on FIG. 6, and the subprocess of FIG. 10, indicated byconnector “G,” each return their processing to the connector indicatedas “F” on FIG. 6 and, thereby, also loop back to step 108 for continuedprocessing of the main loop shown in FIG. 6.

FIG. 7 represents the subprocess called by decision point 110 if thetemperature signal BAKE_TEMP read in step 108 exceeds the desired hightemperature limit for the bake heating element 28 BAKE_HTL. Processingthen moves to decision point 120 at which point the controller 34determines whether the bake heating element 28 is OFF. If the bakeheating element is OFF, the subprocess merely loops back via theconnector shown as “C” whereby processing is returned to step 114 ofFIG. 6.

If the bake heating element 28 is ON, processing moves to step 122 wherethe controller deactivates the bake heating element 28. Processing thenreturns to step 114 of FIG. 6 via the connector shown at “C”. The neteffect of this subprocess is to turn off the bake heating element 28 ifthe bake temperature sensor 32 reads a temperature BAKE_TEMP in excessof the high temperature limit BAKE_HTL as determined in the database104.

FIG. 8 represents the method steps performed when decision point 112determines that the temperature signal emitted by the bake temperaturesensor 32 BAKE_TEMP is less than the desired lower temperature limit forthe bake heating element 28 BAKE_LTL. Processing then moves to decisionpoint 124 where the controller 34 determines whether the broil heatingelement 26 is currently deactivated, i.e., in all OFF state. If so,processing moves to step 126 where the bake heating element is activatedfor its predefined duty cycle as determined by the controller 34 in thedatabase 104.

Specifically, the duty cycle activates the bake heating element 28 for acycle of BAKE_CYCLE seconds of which the bake heating element 28 is onfor BAKE_ON seconds of that total cycle time at a temperature ofBAKE_SET degrees F. It should be noted that the duty cycle of the bakeheating element 28 is started at step 126 and is continuing asprocessing is returned via the connector “C” to step 114 in FIG. 6.

The net effect of the subprocess steps of FIG. 8 is, once adetermination is made that the bake temperature sensor 32 is reading atemperature BAKE_TEMP less than the desired lower temperature limit forthe bake heating element 28 BAKE_LTL, the duty cycle for the bakeheating element 28 is initiated but only after deactivating the broilheating element 26 to ensure that the broil and bake heating element 26and 28 are not actuated at the same time which can cause suddenuncontrolled temperature increases in the baking cavity 12.

FIG. 9 represents the subprocess called by decision point 116 if thetemperature signal BROIL_TEMP read in step 116 exceeds the desired hightemperature limit for the broil heating element 26 BROIL_HTL. Processingthen moves to decision point 128 at which point the controller 34determines whether the broil heating element 26 is OFF. If the broilheating element 26 is OFF, the subprocess merely loops back via theconnector shown as “F” whereby processing is returned via connector “F”to FIG. 6. If the broil heating element 26 is ON, processing moves tostep 130 where the controller 34 deactivates the broil heating element26. Processing then returns to FIG. 6 via the connector shown at “F”.The net effect of this subprocess is to turn off the broil heatingelement 26 if the broil temperature sensor 32 reads a temperatureBROIL_TEMP in excess of the high temperature limit BROIL_HTL asdetermined in the database 104.

FIG. 10 represents the subprocess called a decision point 118 when thecontroller 34 determines that the temperature signal BROIL_TEMP sent bythe broil temperature sensor 30 is less than the desired lowertemperature limit for the broil heating element 26 BROIL_LTL. If so,processing moves along connector “G” from FIG. 6 to FIG. 10 to decisionpoint 132.

At decision point 132, the controller 34 determines whether the bakeheating element 28 is currently activated, i.e., in an ON state. If so,processing returns to FIG. 6 via connector “F” which thereby returnsprocessing to step 108 in FIG. 6. If the bake heating element 28 is notcurrently ON, processing moves to decision point 134 where thecontroller checks whether this is an electric-based oven 10 or agas-based oven 10. If a gas-based oven 10 is detected (i.e., the testwhether the oven is electric fails), processing moves to decision point136. At decision point 136, the controller 34 determines whether thebroil heating element 26 burner purge time has been satisfied (gas-basedsystems require a certain amount of time to elapse before a heatingelement may be reactivated).

If the burner purge time has not been satisfied, processing moves tostep 138 at which time the gas-based broil heating element 26 is purgedin a manner that is well known in the art. After which, processing movesto step 140.

It should also be noted that should the test at decision points 134 and136 be satisfied in the affirmative, i.e., there is an electric-basedoven 10 at issue or the broil heating element 26 purge time has beensatisfied, processing also moves directly to step 140. Also, the cyclecan be optimized for either an electric or gas oven, instead of theillustrated process that checks for the type of oven. If optimized forone type of oven, the process steps specific to the non-optimized ovencan be dropped.

At step 140, the duty cycle for the broil heating element 26 isinitiated in the same manner as described with respect to the bakeheating element 28 duty cycle described in step 126 of FIG. 8.Specifically, a duty cycle of a total cycle time of BROIL_CYCLE secondsof which the broil heating element 26 is activated and emitting heat forBROIL_ON seconds of that total cycle time.

After the duty cycle for the broil heating element 26 is initiated atstep 140, processing returns along the connector “F” to itscorresponding connection point “F” at FIG. 6 which thereafter returnsprocessing to step 108 to repeat the steps of FIG. 6.

The net effect of the steps shown in FIG. 10, once it is establishedthat the temperature BROIL_TEMP detected by the broil temperature sensor30 is less than the desired lower temperature limit BROIL_LTL of thebroil heating element 26, is to leave the bake heating element 28 on ifit is currently on when the subprocess of FIG. 10 is called. Otherwise,if the bake heating element 28 is off, the duty cycle for the broilheating element 26 is immediately initiated at step 140 for anelectric-based oven as determined at decision step 134. For a gas-basedoven 10, the controller 34 ensures that the broil heating element 26purge time has been satisfied and only then initiates the duty cycle forthe broil heating element at step 140.

As stated above, once the duty cycle is initiated at step 140,processing returns via connector “F” to FIG. 6 where the cycle of FIG. 6repeats until the bake time is reached or canceled by the user. Thebroil and bake heating elements 26 and 28 are activated by thecontroller 34 as needed with priority given to the bake heating element28.

The use of dependent sensor for each of the broil and bake heatingelements is preferred over a single sensor for controlling both thebroil and bake heating elements because the broil and bake temperaturesensors 30, 32 are located relatively close to their respective broiland bake heating elements 26, 28, respectively, the temperature sensors30, 32 are available to allow the broil and bake heating elements 26, 28to be independently controlled based upon a signal from thecorresponding temperature sensor 30, 32. The signal from the sensors isalso more indicative of the local temperature of the oven cavitycorresponding to the location of the respective heating element. Thus,greater temperature control and accuracy can be achieved within thebaking cavity 12 of the oven 10.

The example database 104 shown in Table 1 illustrates that differenttemperature set points, i.e., BROIL_SET and BAKE_SET are established forthe corresponding broil temperature sensor 30 and the bake temperaturesensor 32 which can be a function of the location of the particulartemperature sensor 30, 32 to its corresponding heating element 26, 28,respectively. It should also be noted, as previously described, that thepreheat temperatures BROIL_PRE and BRAKE_PRE are preferably greater thanthe corresponding desired target temperature TARGET_TEMP set by the user67 on the control panel 76 at the initiation of the BAKE mode heatingcycle of the oven 10. Additionally, the duty cycles of the broil heatingelement 26 and the bake heating element 28 can be initiated at differentduty cycles as defined by the BROIL_CYCLE, BROIL_ON, BAKE_CYCLE, andBAKE_ON as corresponding to the particular target temperature set pointTARGET_TEMP for the broil heating element 26 and bake heating element 28as determined by the target set points for each heating element, i.e.,BROIL_SET and BAKE_SET, respectively.

The CHOICE BAKE cycle is an option that can be selected along with thenormal BAKE cycle or in lieu of it. That is, the CHOICE BAKE cycle canbe implemented, even repeatedly implemented, at any time during a BAKEcycle or can be initially selected. The CHOICE BAKE cycle reduces theamount of top heat radiated from the broil heating element onto the fooditem to improve the browning performance of the oven. The CHOICE BAKEcycle is implemented by the user selecting the CHOICE BAKE button fromthe cycle keypad 80. Upon the selection of the CHOICE BAKE button,various parameters of the BAKE cycle are adjusted as shown in Table 2 toreduce the top heat emitted by the broil heating element and therebyreduce the top heat.

TABLE 2 Bake Cycle Parameter Adjustments for Choice Bake Cycle Broil SetPoint Adjustment HIGH Band MID Band LOW Band Electric −5° F. −5° F. OFFGas −6° F. OFF OFF

The preferred approach to reducing the top heat radiated by the broilheating element on the food item is to reduce the set point for thebroil heating element. In other words, the BROIL_SET is reduced from itsnormal value during the BAKE mode. The reduction of the broil set pointresults in the broil heating element turning on less than it wouldotherwise during a normal BAKE mode. Since the broil heating element ison less, there is less top heat directly radiated on the top of the fooditem, which reduces the amount of browning.

As is shown in Table 2, the amount the set point is reduced takes intoconsideration both the type of broil heating element (electric or gas)and the temperature band range of the TARGET_TEMP. For an electric broilheating element, the BROIL_SET is reduced 5° F. from the values shown inTable 1 for the TARGET_TEMP for both the HIGH and MID temperature bands.For example, if the TARGET_TEMP is 350° F., the BROIL_SET is 329° F.,which is 5° F. less than the 334° F. value shown in Table 1. For the LOWband, the broil heating element is turned off because the bake heatingelement can supply sufficient heat to maintain the cooking chamberwithin the desired temperature range.

For a gas broil heating element, the BROIL_SET is reduced 6° F. from thevalues shown in Table 1 for the TARGET_TEMP for the HIGH temperatureband. The broil gas element is turned OFF for the MID and the LOWtemperature bands. The heat output of the bake gas element is turned offbecause the gas bake heating element can supply sufficient heat tomaintain the cooking chamber within the desired temperature ranges. Allthings being equal, the gas elements normally output a greater amount ofheat than the electric elements.

Although not shown in Table 2, in addition to the change in theBROIL_SET parameter, it is preferred that the duty cycle, as representedby the BROIL_ON parameter of Table 1, is reduced by a predeterminedamount, preferably approximately 50%, for both the electric and gasbroil heating elements and for all of the temperature bands (HIGH, MID,and LOW). For example, as shown in Table 1, the BROIL_ON time for the350° F. TARGET_TEMP is 35 seconds for a cycle time of 60 seconds for theBAKE cycle. When the CHOICE BAKE cycle is selected, the BROIL_ON time isreduced approximately 50% to about 17 seconds. The reduction of the dutycycle necessarily results in a corresponding reduction in the top heat.

The turning OFF of the broil heating element can be accomplished in manydifferent ways. For example, the BROIL_ON parameter can be set to 0,which would prevent the broil heating element from turning on.Alternatively, the controller, which is already pre-programmed withwhether the broil heating element is gas or electric, can detect theselection of the CHOICE BAKE cycle and then check to see if theTARGET_TEMP is in one of the temperature ranges (HIGH, MID, and LOW)that requires the broil heating element to be turned off and then shutsoff power to the broil heating element as long as the CHOICE BAKE cycleis selected.

While it is preferred that, upon the selection of the CHOICE BAKE cycle,the top heat is reduced by both reducing the value for the BROIL_SETparameter and the value for the BROIL_ON time, it is within the scope ofthe invention to reduce the value of only one of the parameters.

The CHOICE BAKE cycle as described represents a substantial improvementin the browning performance of an oven dual-element oven. The reductionof top heat associated with the activation of the CHOICE BAKE cycleprovides for the more traditional browning effect while taking advantageof the more even temperature distribution associated with thedual-element oven.

Another advantage of the CHOICE BAKE cycle is that it can be turned onand off as desired by the user. Since the CHOICE BAKE cycle isimplemented by changing the standard values for the BROIL_ON andBROIL_SET parameters of the standard BAKE cycle, the user can easilyswitch between the two cycles. For example, if the user begins byselecting the BAKE cycle and then decides that too much browning isoccurring, say by observing the food item, the user can press the CHOICEBAKE button to activate the CHOICE BAKE cycle. If the user starts byselecting the CHOICE BAKE cycle and then decides that more browning isneeded, the user can select the BAKE cycle by selecting the BAKE button.It is within the scope of the invention for the CHOICE BAKE button towork as a toggle. If the CHOICE BAKE cycle is already selected and theChoice Bake button is selected, the controller switches from the CHOICEBAKE cycle to the BAKE cycle by replacing the values of Table 2 with thevalues of Table 1. Another selection of the CHOICE BAKE button willresult in the controller switching from the BAKE cycle back to theCHOICE BAKE cycle by using the values of Table 2 for the BROIL_ON andBROIL_SET.

The ability to turn the CHOICE BAKE cycle off and on as the user seesfit is greatly beneficial to the user. It lets the user manually controlthe amount of browning based on the user's baking experience withoutfundamentally changing the underlying baking cycle. That is, thebrowning can be controlled as desired without changing the bake time orthe bake temperature required to properly cook the food item. With theinvention, the user can have a perfectly cooked and browned cake.

In the preferred embodiment, dual sensors are used to individually sensethe baking cavity temperature near each of the heating elements sincethis yields the greatest accuracy. However, it is within the scope ofthe invention for a single temperature sensor to be used. The inventionis useful whenever the broil heating element is used during the standardbake cycle regardless of the number of temperature sensors.

While it is anticipated that the primary use of the invention will be toreduce the top heat to improve the browning performance of the oven, itis also within the scope of the invention to use the CHOICE BAKE optionto increase the top heat. Since the user is now being given control overthe top heat, it is anticipated that some users will likelyunderestimate the amount of top heat and needed for proper browning andleave the CHOICE BAKE cycle on too long, resulting in the inability toapply sufficient top heat by the end of the baking time to obtain thedesired browning. There may also be an occasion where additional topheat is desired without any prior reduction in the top heat.

Thus, the users can be given the option to use the CHOICE BAKE button toincrease the top heat. This can easily be done in many different ways.The CHOICE BAKE button can be a three position switch, with one positioncorresponding to increased top heat, another to reduced top heat, and athird to the top heat provided by the predetermined protocol. The switchcould even be a four position that also provided for completely turningoff the top heat. However, it is more desirable to implement this in theprotocol for the reduced top heat. Multiple switches could be usedinstead of a single switch. Also, a top heat control knob could be usedhaving positions corresponding to reduced or increased top heat.

The increasing of the top heat can be implemented in the same manner asthe reducing of the top heat previously described. That is the set pointcan be increased or the duty cycle increased. The amount of theincreases will depend on the particular output of the broil heatingelement, just like the reduction values. The increase in these valuescan also be a function of the bake temperature, just like the reductionvalues.

While the invention has been specifically described in connection withcertain specific embodiments thereof, it is to be understood that thisis by way of illustration and not of limitation, and the scope of theappended claims should be construed as broadly as the prior art willpermit.

What is claimed is:
 1. An oven for baking food according to a bake cyclehaving user selected time and temperature parameters, the ovencomprising: a housing defining an open-face baking cavity formed byopposing top and bottom walls, opposing side walls extending between thetop and bottom walls, and a rear wall opposing the open face; a doormovably mounted to the housing for movement between an opened and aclosed position to selectively close the baking cavity open face; a bakeheating element positioned adjacent the bottom wall for introducingbottom heat into the baking cavity; a broil heating element positionedadjacent the top wall for introducing top heat into the baking cavity;and a controller for controlling the activation of the broil heatingelement by cycling the broil heating element ON and OFF to implement thebake cycle and having a user-operable switch, the selection of whichincreases or decreases the top heat radiated by the broil heatingelement while the switch is selected and the deselection of the switchterminates the reduced top heat, to thereby permit the user toselectively control the top heat and the browning performance of theoven.
 2. The oven according to claim 1 wherein the controller controlsthe activation of the broil and bake heating elements by cycling thebroil and bake heating elements ON and OFF according to a predeterminedprotocol to implement the bake cycle according to the user-selected timeand temperature, and the selection of the user-operable switch reducesor increases the cumulative top heat radiated by the broil heatingelement relative to the cumulative top heat outputted according to thepredetermined protocol.
 3. The oven according to claim 2 wherein theselection of the user-operable switch reduces or increases the overalltime that the broil heating element is ON relative to overall time thebroil heating element is ON according to the predetermined protocol. 4.The oven according to claim 3 wherein the deselection of theuser-operable switch returns the top heat radiated by the broil heatingelement to that determined by the predetermined protocol.
 5. The ovenaccording to claim 4 wherein the deselection of the user-operable switchreturns the cumulative time that the broil heating element is on to thetime determined by the predetermined protocol.
 6. The oven according toclaim 2 wherein the predetermined protocol comprises at least oneparameter for controlling the activation of the broil and heatingelements and the selection of the user-operable switch alters the atleast one parameter to reduce or increase the cumulative top heatradiated by the broil heating element.
 7. The oven according to claim 6wherein the at least one parameter is a temperature set point having aninitial value at which the broil heating element is turned ON and theselection of the user-operable switch reduces or increases thetemperature set point from the initial value.
 8. The oven according toclaim 7 wherein the deselection of the user-operable switch returns thetemperature set point to its initial value.
 9. The oven according toclaim 7 wherein the at least one parameter is a duty cycle having aninitial value and the selection of the user-operable switch reduces orincreases the initial value of the duty cycle.
 10. The oven according toclaim 9 wherein the deselection of the user-operable switch returns theduty cycle to its initial value.
 11. The oven according to claim 6wherein the at least one parameter is a duty cycle having an initialvalue and the selection of the user-operable switch reduces or increasesthe initial value of the duty cycle.
 12. The oven according to claim 11wherein the deselection of the user-operable switch returns the dutycycle to its initial value.
 13. The oven according to claim 2 andfurther comprising a first temperature sensor coupled to the controllerand positioned within the baking cavity near the broil heating elementfor sensing a localized baking cavity temperature near the broil heatingelement and a second temperature sensor coupled to the controller andpositioned within the baking cavity near the bake heating element forsensing a localized baking cavity temperature near the bake heatingelement, whereby the controller independently controls the actuation ofthe broil and bake heating elements based on their localizedtemperatures.
 14. The oven according to claim 13 wherein thepredetermined protocol comprises a broil temperature set point and abake temperature set point, wherein when the localized broil temperatureis less than the broil temperature set point, the controller actuatesthe broil heating element, and when the localized bake temperature isless than the bake temperature set point, the controller actuates thebake heating element.
 15. The oven according to claim 14 wherein theselection of the user-operable switch reduces or increases the value ofthe broil temperature set point.
 16. The oven according to claim 15wherein the deselection of the user-operable switch returns thetemperature set point to its prior value.
 17. The oven according toclaim 16 wherein the selection of the user-operable switch reduces orincreases the duty cycle for the broil heating element.
 18. The ovenaccording to claim 17 wherein the deselection of the user-operableswitch returns the duty cycle to its prior value.
 19. A method forcontrolling the browning performance of an oven comprising a bakingcavity having a broil element positioned near a top wall of the ovencavity for radiating top heat into the baking cavity, a bake elementpositioned near a bottom wall of the baking cavity for radiating bottomheat into the baking cavity, and a controller for actuating the bake andbroil heating elements ON and OFF, the method comprising: implementing abaking cycle that maintains the temperature of the baking cavity at apredetermined bake temperature by controlling the cycling ON and OFF ofthe bake and broil heating elements; and selectively reducing orincreasing the cumulative top heat radiated by the broil heating elementfor at least part of the bake cycle in response to a user input.
 20. Themethod of claim 19 wherein the top heat is reduced or increased for theentire bake cycle in response to the user input.
 21. The method of claim19 wherein the predetermined bake temperature is selected by the user.22. The method of claim 19 wherein the implementing of the bake cyclecomprises setting a broil temperature set point corresponding to thepredetermined bake temperature.
 23. The method of claim 22 wherein thecontroller sets the broil temperature set point.
 24. The method of claim22 wherein the selective reducing or increasing of the top heatcomprises reducing or increasing, respectively, the broil temperatureset point.
 25. The method of claim 24 wherein the implementing of thebake cycle comprises setting a duty cycle for the broil heating elementbased on the predetermined bake temperature.
 26. The method of claim 25wherein the duty cycle varies as a function of magnitude of thepredetermined bake temperature.
 27. The method of claim 26 wherein thepredetermined bake temperature is limited to at least two temperatureranges.
 28. The method of claim 27 wherein the duty cycle varies as afunction of the temperature range.
 29. The method of claim 28 whereinthe reduction of the broil temperature set point varies as a function ofthe temperature range.
 30. The method of claim 29 wherein the reductionof the broil temperature set point includes reducing the broiltemperature set point such that the broil heating element is not turnedON during the selective reduction of top heat.
 31. The method of claim19 wherein the implementing of the bake cycle comprises setting a dutycycle for the broil heating element based on the predetermined baketemperature.
 32. The method of claim 31 wherein the duty cycle varies asa function of magnitude of the predetermined bake temperature.
 33. Themethod of claim 32 wherein the predetermined bake temperature is limitedto at least two temperature ranges.
 34. The method of claim 33 whereinthe duty cycle varies as a function of the temperature range.
 35. Themethod of claim 19 wherein the user input comprises the selection of aswitch coupled to the controller by the user.
 36. An oven for bakingfood according to a bake cycle having user selected time and temperatureparameters, the oven comprising: a housing defining a baking cavity; abake heating element positioned adjacent a lower portion of the bakingcavity for introducing bottom heat into the baking cavity; a broilheating element positioned adjacent an upper portion of the bakingcavity for introducing top heat into the baking cavity; and a controlpanel comprising a bake mode selector for selecting the desired bakemode, a bake temperature selector for selecting the desired bakingtemperature, a bake time selector for selecting the desired bake time,and a top heat adjustment selector for adjusting the top heat relativeto the amount of top heat determined by the selected bake mode.
 37. Theoven according to claim 36 wherein the selection of the top heatadjustment selector on the control panel increases or decreases theoutputted top heat relative to the outputted top heat according to theselected bake mode.
 38. The oven according to claim 37 wherein theselection of the top heat adjust selector alters at least one parameterof the selected bake mode.
 39. The oven according to claim 38 whereinthe at least one parameter comprises at least one of a temperature setpoint and a duty cycle.
 40. The oven according to claim 39 wherein thetemperature set point is a localized set point for the broil heatingelement.
 41. The oven according to claim 36 wherein the top heatadjustment selector is a switch.
 42. The oven according to claim 41wherein the switch is a button.
 43. The oven according to claim 36wherein the top heat adjustment selector is a knob.
 44. The ovenaccording to claim 43 wherein the bake mode selector is a knob.
 45. Theoven according to claim 44 wherein the same knob is used for the topheat adjustment selector and the bake mode selector.